Rewrite ${((9^{6})(4^{-5}))^{-7}}$ in the form ${9^n \times 4^m}$.
Answer: ${ ((9^{6})(4^{-5}))^{-7} = (9^{(6)(-7)})(4^{(-5)(-7)})} $ ${\hphantom{ ((9^{6})(4^{-5}))^{-7}} = 9^{-42} \times 4^{35}} $